{"id":3499,"date":"2020-11-25T12:04:28","date_gmt":"2020-11-25T17:04:28","guid":{"rendered":"http:\/\/matroidunion.org\/?p=3499"},"modified":"2020-12-09T15:22:34","modified_gmt":"2020-12-09T20:22:34","slug":"online-talk-johannes-carmesin","status":"publish","type":"post","link":"https:\/\/matroidunion.org\/?p=3499","title":{"rendered":"Online talk: Johannes Carmesin"},"content":{"rendered":"\n<h5><strong>Monday, November 30,<\/strong> <strong>3pm ET<\/strong> (8pm GMT, 9am Tue NZDT)<br \/><a href=\"http:\/\/web.mat.bham.ac.uk\/J.Carmesin\/\"><strong>Johannes Carmesin<\/strong><\/a>, University of Birmingham<br \/><strong>Matroids and embedding graphs in surfaces<\/strong><\/h5>\n<h5><a href=\"https:\/\/youtu.be\/WCM6Rh0-hWE\"><b>Youtube<\/b><\/a><\/h5>\n<h5>\u00a0<\/h5>\n<h5><b><\/b><strong>Abstract:<\/strong><\/h5>\n<h5>Given a graph, how do we construct a surface so that the graph embeds in that surface in an optimal way? Thomassen showed that for minimum genus as optimality criterion, this problem would be NP-hard. Instead of minimum genus, here we use local planarity &#8212; and provide a polynomial algorithm.<\/h5>\n<h5>\u00a0<\/h5>\n<h5>Our embedding method is based on Whitney&#8217;s trick to use matroids to construct embeddings in the plane. Consequently we obtain a characterisation of the graphs admitting locally planar embeddings in surfaces in terms of a certain matroid being co-graphic.<\/h5>\n","protected":false},"excerpt":{"rendered":"<p>Monday, November 30, 3pm ET (8pm GMT, 9am Tue NZDT)Johannes Carmesin, University of BirminghamMatroids and embedding graphs in surfaces Youtube \u00a0 Abstract: Given a graph, how do we construct a surface so that the graph embeds in that surface in &hellip; <a href=\"https:\/\/matroidunion.org\/?p=3499\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":19,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[11],"class_list":["post-3499","post","type-post","status-publish","format-standard","hentry","category-matroids","tag-online-talks"],"_links":{"self":[{"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/posts\/3499","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/matroidunion.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3499"}],"version-history":[{"count":5,"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/posts\/3499\/revisions"}],"predecessor-version":[{"id":3581,"href":"https:\/\/matroidunion.org\/index.php?rest_route=\/wp\/v2\/posts\/3499\/revisions\/3581"}],"wp:attachment":[{"href":"https:\/\/matroidunion.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3499"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/matroidunion.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3499"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/matroidunion.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3499"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}